1. Field
The following description relates to an apparatus for controlling channels of an Internet protocol television (IPTV) service by selecting and pre-joining channels based on data regarding a channel zapping pattern of a user, thereby efficiently reducing channel zapping time, and a method of pre-joining channels using the apparatus.
2. Description of the Related Art
In an Internet protocol television (IPTV) environment, a channel broadcasting service is provided in multicast, and IP multicast protocols such as protocol independent multicast (PIM), Internet group management protocol (IGMP) and the like are used between backbone of an IP network and an edge router.
In the IPTV channel broadcasting service, broadcast data is transmitted in multicast stream through a broadcast channel from a head end to a set-top box (STB). Here, a user may join a broadcast channel multicast group to receive the broadcast data.
Multicast is a transmission method in which data is replicated for simultaneous delivery to more than one destination, thereby reducing network bandwidth. In the IPTV broadcasting service, a streaming server of a head end that transmits a broadcast channel is a multicast source, and a set-top box that is willing to view the broadcast channel is a receiver. The multicast source transmits broadcast data through a broadcast channel to a multicast group address as a destination address, and a user that is willing to receive the transmitted broadcast data joins a multicast group of the corresponding broadcast channel and receives various contents.
In the IPTV broadcasting service, all nodes that respectively transmit, transfer, and receive broadcasting through the same broadcast channel on networks constitute a multicast group. Therefore, when a user issues a request for a channel to watch, a corresponding broadcast channel joins a multicast group.
According to a prior art, to reduce IPTV channel zapping time, not only a currently viewed channel but also adjoining channels are pre-joined based on characteristics of multicast. That is, in consideration of the fact that the user usually selects a channel by pressing up/down is buttons on a remote controller, data of channels to be next selected is transferred to a home gateway in advance.
However, if the user changes the channel using buttons other than the up/down buttons (a preset button or number buttons), channel zapping time reduction cannot be achieved. Moreover, in the above method, because several adjacent channels of a current viewed channel are additionally joined, multicast traffic of the corresponding adjacent channels is additionally transmitted to the home gateway, and thus network resource cost increases.
To overcome the above mentioned drawbacks, a method of providing an expected channel list based on the rating statistics obtained by a rating server has been proposed. However, although in some circumstance, the pre-joining through the rating server can advantageously pre-join fewer channels than the method of pre-joining adjoining channels and network resource cost can be reduced, the pre-joining through the rating sever may be less meaningful to a user because the rating server does not reflect their personally preferred channels.
Hence, a need for more efficiently improving channel zapping time has arisen.